Europe’s Winemakers Break With Tradition as Temperatures Rise
PARIS—Volatile summer weather in Europe, including the record-breaking heat waves that recently scorched the continent, is wreaking havoc on wine country.
Temperatures rose to an unprecedented high of 115 degrees in parts of France, causing grapes to ripen before their acidity fully developed, a crucial part of any wine’s flavor profile. This summer’s drought followed the freak storms last year that hit the wine-growing regions of Bordeaux, Cognac, and Champagne. In Italy, a summer of wildfires, hailstorms and other extreme weather events have shredded vineyards.
Paola Del Casale said hailstones destroyed at least half of the season’s production at her family’s winery along the Adriatic coast.
“I have never seen hailstorms like this before,” Ms. Del Casale said, adding she will have to replant damaged young vines and wait up to two years for them to produce viable grapes. “It’s like I’ve lost this year completely.”
Regions like Tuscany and Bordeaux have long depended on serene summers to produce some of the world’s finest wine, year after year. Reliable conditions allowed winemakers to develop strict codes for where and how to produce wine.
Today’s turbulent climate, however, is now forcing vineyards to break with traditions that have defined winemaking on the continent for generations.
Winemakers are harvesting grapes more than a month ahead of schedule, sometimes in the middle of the night when temperatures are cooler. Some French winemakers are planting hardier grapes and re-evaluating some of the more sensitive—and celebrated—varietals such as Riesling and Merlot. In Italy, some are relocating vineyards uphill, where microclimates are cooler, and are experimenting with new technology.
In Germany, production of the French classic Merlot has more than tripled in the past two decades, as the weather warms.
Researchers across the region are investigating whether it’s possible to take advantage of climate change by shifting more wine production to Northern Europe, but they are also running into hurdles. Climate instability across the continent has heightened uncertainty over quality and annual yield.
“It’s impossible to determine the season’s course until the very last moment,” said Giordano Zinzani, president of a local wine consortium in northern Italy.
Winemakers say the measures some of them have taken so far are a band-aid at best, not a lasting solution given the challenges they face.
Rising temperatures are causing grapes to ripen earlier, accelerating harvest times.
Hotter temperatures that allow grapes to bloom earlier also leave them exposed to spring frosts, which tend to hang around longer in northern latitudes. Dramatic swings in temperature also create conditions for fungal rot, pests and drought.
Grapes that ripen more quickly in the warming weather can also develop higher levels of sugar and alcohol, overpowering their acidity, a crucial flavor profile in nearly all wines. Across Italy, alcohol levels have risen a percentage point in the last 30 years, according to national agricultural group Coldiretti. In some regions, classics like Chianti and Barolo have seen even larger spikes.
As a consequence, the harvest schedule has crept up by about a month in Italy, Germany and France, from October to early September or late August.
Pierre Trimbach, an Alsatian winemaker who grows Riesling and now harvests his grapes in the beginning of September, says the accelerated timeline comes at a steep price. “You lose the really citrus, really grapefruit flavor,” he explained.
Mr. Trimbach now says he fears the lower acidity levels will mean Riesling, a wine traditionally stored for decades, won’t age as well.
“Riesling’s great asset is being a vin de garde—a wine you keep for 20, 30, 40 years. Today, you can open magnificent 40-year-old Rieslings. Will the wines produced today be as beautiful in 40 years? No one knows,” he said.
If the changing climate forces the region’s winemakers to stop growing Riesling altogether, Mr. Trimbach questions whether producers could really be considered Alsatian any more.
In the Bordeaux region, winemakers voted to go against convention and approve seven late-ripening grape varieties for use in Bordeaux-labeled wine, including Touriga Nacional, a Portuguese red, and Albariño, a white grape grown in Spain.
Bordeaux winemaker Vincent Gauthier has experimented with varietals that allow him to take a different tack than some and extend his growing schedule to as late as November, in an effort to preserve subtler and more citrusy flavors. “The ancient Bordeaux varietals that you’d know, Cabernet, Merlot, they ripen too much. They increasingly produce wines that feel Californian—too rich,” said Mr. Gauthier.
He now plants two hectares of Carménère and Petit Verdot, which can be harvested as late as early November. He’s not alone. In 2000, Petit Verdot was planted on 375 hectares in Bordeaux. By 2018, it covered 1,093 hectares.
The break with tradition is raising hackles in a region deeply vested in its heritage, and many winemakers aren’t ready to join in.
whose vineyards lie in Saint-Émilion, says he is no hurry to adopt foreign imports and is doubling down on using Cabernet Franc and Cabernet Sauvignon grapes, as his father did. “The grape vine is a Mediterranean plant. She requires a little heat and a little drought,” he said.
In Italy, long periods of drought are leading farmers to adopt new irrigation systems and humidity sensors. Some have begun cultivating grapes at high altitudes where cooler temperatures are ideal for retaining acidity and limiting the spread of diseases, molds and pests.
Researchers at Hochschule Geisenheim University, near Frankfurt, meanwhile, have developed technologies to simulate winegrowing conditions predicted for 2050, with their higher levels of carbon dioxide. By blowing a constant stream of CO2 over test crops of Riesling and Cabernet Sauvignon, they have produced juicier, larger clusters of grapes.
But while a higher level of CO2 has a fertilizing effect and increases photosynthesis, that factor would be severely undercut by expected water shortages, which stunt a vine’s development. This could preclude Germany from becoming Europe’s next wine basket, as some onlookers hoping to turn a profit on the warming climate are betting.
“People perceive it as, we’ll have breakfast outside and watch palm trees wave gently in the breeze. But we are still at a northern latitude,” said Claudia Kammann, an ecologist who worked on the study. “We will not be a copy of the Mediterranean, regardless of what people think.”